The gathering, organised on Facebook just two hours earlier, was in response to the murder of 12 journalists at the French satirical newspaper Charlie Hebdo. It was held at the same time as large vigils in other cities around Europe.

From 6pm onwards hundreds of individuals arrived at London’s main square, mainly holding the alreadyubiquitous “Je Suis Charlie” signs – some were printed out, while others were scrawled on cardboard or displayed on iPad screens.

With no apparent co-ordination, the crowd began to hold pens aloft in a gesture of solidarity.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

The crowd remained almost completely silent in Trafalgar Square for over an hour.

Matthew Tucker / BuzzFeed

The only noise in one of London's busiest areas came from the passing traffic and the bells of St Martin-in-the-Fields, the nearby church.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

Some people recreated what they considered to be the only possible politically correct cartoon.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

This was a reference to an old New Yorker cartoon that went viral following Wednesday's attack on the newspaper, which is known for its controversial attacks on many groups.

The silence was only broken by the occasional gentle rendition of "La Marseillaise", the French national anthem.

The only other interruption was when an individual shouted "liberté d'expression!", which was cheered by the crowd.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

Some French nationals in the crowd struggled to come to terms with the shooting.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

“I am still shaking,” said Marie Humbert (left), 25, a French graphic designer who lives in London.

“This is an attack on freedom. You have to understand the French mentality and what was… what is Charlie," she said, correcting herself for referring to the magazine in the past tense. “They were people who would not shut their mouths. If something is wrong they would laugh and makes jokes about it. You may see that in Afghanistan or Pakistan but in Paris you expect to be able to express yourself."

Others held up covers of Charlie Hebdo.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

Ben Mercier, 29, a French financial analyst, was holding up an old copy of the newspaper: “It’s very satirical journal which treats the actualité from an angle where everyone looks back. It’s absolutely not politically correct."

"I was a big fan of [cartoonist] Cabu and [editor] Charb and I am very sad they are dead now.”

Rufus Dayglo said he turned out in solidarity with fellow artists to oppose the “completely medieval” gunmen who targeted the newspaper.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

“Places like France have a long tradition of cutting satire but I don’t think they can ever surrender to brutality or sheer medieval stupidity," said the artist, who works for 2000AD and DC Comics.

He urged the media to respond by distributing Charlie Hebdo's work.

Matthew Tucker / BuzzFeed

"It’s our job as artists and journalists to provoke debate and sometimes people pay the price for that. I hope that the media will show their work and provoke their work as opposed to just showing carnage.”

Meanwhile, the vigil continued in silence.

Matthew Tucker / BuzzFeed

Matthew Tucker / BuzzFeed

Jim Waterson is a politics editor for BuzzFeed News and is based in London.